The study of the Earth's physical substances and structure is called geology. Geology encompasses the examination of the Earth’s materials, such as rocks and minerals, and the processes that shape the Earth's surface over time, including plate tectonics, erosion, and sedimentation. Geologists analyze geological formations, investigate natural resources, and study the history of the Earth through fossils and strata. Understanding geology is crucial for resource management, environmental protection, and assessing geological hazards like earthquakes and volcanoes.